Currently, light extraction efficiency of an Organic Light-Emitting Diode (OILED) display device is relatively low, in part because of a substrate mode/waveguide mode caused by the structure of the OLED. The essence of the substrate mode/waveguide mode is that in the case that light is incident from an optically denser medium onto an optically thinner medium and in the case that an incident angle of the light is greater than a critical angle, the light will be totally reflected and the light cannot emerge from the optically denser medium.
FIG. 1 is a structural schematic view illustrating a display panel. As shown in FIG. 1, in the case that light is incident from a transparent electrode to a glass substrate 02 and the transparent electrode is the optically denser medium compared to the glass substrate 02 and in the case that the incident angle of the light is greater than the critical angle, the light will be totally reflected on a contact surface of the transparent electrode and the glass substrate 02, and thus, the light cannot emerge from the glass substrate 02 but emerges from a sealant 03 for bonding upper and lower substrates of the display panel, so that light extraction efficiency of the display panel is reduced.